The present invention relates to an ultraviolet ray absorbing agent (UV absorber) comprising a spiro compound specific in structure, as an active ingredient.
Up to now several benzophenone compounds and benzotriazole compounds have been disclosed as UV absorbers and some of them have been commercialized already.
However, these known UV absorbers involve such problems that some of them exhibit low UV absorption power, some are inferior in light resistance, some have colors which will result in color contamination of materials when incorporated thereinto for shielding, and some have low light stability, high sublimability, or low affinity for organic materials. Thus, satisfactory effect has not always been obtained with these UV absorbers.